1. Field of the Invention
The present invention is directd to a gate valve having an integral body with axially aligned inlet, valving and outlet ports wherein a gate is slidable between open and closed positions relative to the valving port for controlling the flow of media therethrough. A pair of axially aligned cylinders are formed integral with the body and are normal to and in open communication with the valving port for carrying the gate, wherein a piston in each of said cylinders is secured to an opposite end of the gate for shifting the gate between open and closed positions in response to pressure media selectively introduced into one or the other of the cylinders.
2. Description of the Prior Art
Gate valves of the prior art generally include valve bodies having coaxial inlet, valving and outlet ports and an elongate neck which projects outwardly from the valving port. The valving member or gate is in the general shape of a wedge which is adapted to be shifted between positions of interfering and noninterfering relationship with the media passageway of the valve to open and close the valve to media flow. The gate is secured to and carried by an elongate, threaded actuator stem coaxial with the neck and received by a threaded, stem-receptive aperture in the neck of the valve. A stem-receptive nut is rotatably mounted external to the valve body seal, and rotation imparted to said external stem nut imparts endwise axial movement to the stem to shift the gate between open and closed positions. The stem may be manually turned by means such as a hand-wheel or the like mounted thereon, or on larger valves it may be controlled by externally applied forces generated by electric motors or the like.
Examples of the gate valves of the prior art are disclosed in my earlier U.S. Pat. Nos. 2,810,494 and 2,617,554.